1. Field of the Invention
Embodiments of the invention relate to the field of device processing. More particularly, the present invention relates to a method, system and structure for patterning a substrate.
2. Discussion of Related Art
Conventional plasma doping systems (PLAD) are employed to perform both ion implantation as well as thin film deposition on a substrate. However, the ability to coat three dimensional structures (3-D) faces challenges using conventional PLAD technology. In particular, conformal coating may be difficult to achieve. When used as a deposition tool, previous work has demonstrated that high quality layers may be deposited upon 3-D structures such as trenches that are disposed in a substrate surface region. However, in order to achieve 3-D doping of 3-D structures, such as fin type field effect transistors (FinFET) control of the angular distribution of knock-on ions that may be used to produce high quality layers is desirable. In conventional PLAD, the angle of incidence of knock-on ions that may impinge upon the substrate is typically close to perpendicular to a plane of the substrate such that vertical and other surfaces inclined at an angle with respect to the substrate plane receive ions at a different relative angle as compared to surfaces that are parallel to the substrate plane. Accordingly, uniform exposure of all surfaces of a 3-D structure to knock on ions in a PLAD system is not generally achieved.
This problem may be addressed by performing a separate ion treatment procedure in a different apparatus that provides ions over a range of angles of incidence, such as a tool having a plasma sheath modifier. More uniform coverage of 3-D structures may then be achieved, with the drawback that the process requires separate tools to achieve the desired result for coatings of 3-D structures. In view of the above, it will be appreciated that there is a need to develop less complex and costly methods for treating 3-D structures on a substrate surface.